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Version 17
Safe-E-
Stop™
User Guide
8.2.2 Single-Channel Connections Example when not using the COMM LOSS Relays
The following configuration does not use the SIL3 function of the COMM LOSS relays but does use the
systematic capability of 3 provided by the E-Stop relays.
Where a strong process is in place that ensures the users confirm that the PSD is LINKED before starting to work,
the use of the COMM LOSS relays may not be needed. The Ethernet bus may be used to give visual feedback of
PSD status or total number of PSDs linked, or to allow the green button to light a lamp, etc. This makes it possible
to run the machine with the hard-wired E-Stop switch in use and no PSD in use.
The single channel connection method below will not provide protection against an external wiring fault.
Figure 13: MSD Typical Single-Channel Connections When Not Using the COMM LOSS Relays